> -----Original Message-----
> From: Svein Erling Tysvaer
> [mailto:svein.erling.tysvaer@...]
> Sent: Friday, January 10, 2003 5:47 AM
> To: ib-support@yahoogroups.com
> Subject: Re: [ib-support] Re: Update
>
> IB/Fb needs a plan to execute whether you specify it explicitly or not.
>
> >Should I do that ?
>
> Normally not, but you should examine the generated plan, e.g. by
> preparing
> the statements using IB_SQL (free from www.ibobjects.com).

Michael,
Another great tool that has really helped me in my transition to Firebird
and understanding how
its optimizer and plans work is Craig Stuntz' "PLANalyzer":
http://codecentral.borland.com/codecentral/ccweb.exe/author?authorid=4593

There is documentation with it where Craig goes in pretty deep as to how to
design your indexes for
maximum efficiency. The tool would especially help you in you current
problem, because you can enter a query against your
live database, see the plans that are generated, along with selectivity
estimations (your single value index question), then have it analyze the
execution, showing both time to prepare as well as execute/fetch. It is
very instructional and
definitely worth the download!

HTH,
Brian